ISOLATION AND CHARACTERIZATION OF AN ALTERNATIVELY-SPLICED RAT AMELOGENIN CDNA-LRAP - A HIGHLY CONSERVED, FUNCTIONAL ALTERNATIVELY-SPLICED AMELOGENIN

A cDNA coding for a 59 amino acid polypeptide containing both the carboxy- and amino-termini, but lacking the central domain, of the rat tooth enamel matrix protein, amelogenin, was cloned and sequenced. The deduced polypeptide sequence indicates that this cDNA was derived from an amelogenin It?JA molecule by using an alternative intra-exonic 3' splice acceptor site. This alternatively spliced product is almost identical to products previously identified in both cow and mouse enamel organs: the leucine-rich amelogenin peptide (LRAP). The conservation of this truncated polypeptide across the species suggests that it may have an important role in the formation of tooth enamel.